BEIRUT (AP)—The Islamic State militant group is advancing in central Syria, seizing control of a town that lies near a highway leading to the capital, Damascus, and attacking another, activists and the group said Sunday.

The capture of Mahin, in the central Homs province, and the push toward majority-Christian town of Sadad, marks a new advance of the Islamic State group beyond its strongholds in northern and eastern Syria. The militant group had seized control of the ancient city of Palmyra in May and a neighbouring village.

The new Islamic State expansion comes despite Russian airstrikes in Syria, which Moscow says target Islamic State and other terrorist groups. For the most part, the Russian airstrikes, in their fifth week, have targeted Western-backed rebel groups and other Islamist groups.

Islamic State militants have also made recent gains in Aleppo, seizing villages from other rebel groups and controlling a section of a strategic highway that serves as a supply route into government-controlled areas of Aleppo.

In its fifth year, the Syrian civil war has claimed more than 250,000 lives and caused half of the pre-war population to become displaced or refugees in the bloody violence that also left over a million injured. What started out as protests against the government of President Bashar Assad in 2011 has turned into a bloody civil war that has also attracted militants from around the world, fanned by rising sectarianism in the region.

Syrian men check the destruction following a reported airstrike by Syrian government forces on the rebel-held town of Douma, on the eastern edges of the capital Damascus, on Sunday. The capture of Mahin, in the central Homs province, and the push toward majority-Christian town of Sadad, marks a new advance of the Islamic State group beyond its strongholds in northern and eastern Syria.